Tonneau cover with torsion element

ABSTRACT

A tonneau cover that includes a first panel, a second panel, a hinge between the first panel and the second panel, and a torsion element between the first panel and the second panel. The torsion element applies an urging force onto one or both of the first panel and the second panel during movement of the first panel and/or the second panel about the hinge.

FIELD

These teachings relate to a cover for a vehicle cargo area, and moreparticularly to a cover with a torsion element that assists with movingone or more panels thereof.

BACKGROUND

Some vehicles, like pick-up trucks, have an open-topped bed or cargoarea that may be used for storing or transporting cargo. A cover, suchas a tonneau cover or topper, may be placed over the cargo area. Thecover may be opened to access the cargo and/or the inside of the cargoarea and closed to conceal the cargo from view and/or to prevent fluidand/or debris from entering the cargo area.

Some covers include one or more panels that can be moved or repositionedto access the cargo and/or the inside of the cargo area. Some of thesepanels may be heavy and large, which can make them unwieldy anddifficult to move. Likewise, moving or repositioning the one or morepanels to close or cover the cargo area may be difficult.

Some covers include two or more panels that must be moved and stacked ontop of each other to access the cargo and/or the inside of the cargoarea. The more panels that a cover has, the heavier the stacked weightof the panels becomes, which may be difficult for an operator tocompletely open the cover to access the cargo area. Likewise, unstackingthe panels to cover the cargo area may be difficult

Accordingly, it may be desirable to have a cover that overcomes at leastsome of the aforementioned challenges with opening and closing the oneor more panels of a cover.

SUMMARY

These teachings relate to a cover that has one or more panels. The coverincludes one or more torsion elements that assist with moving the one ormore panels between an open and closed configuration. The cover may haveonly one panel (e.g., no more than one panel) or the cover may have twoor more panels. One or more torsion elements may be provided between twoor more panels. One or more torsion elements may be provided between apanel and a portion of a vehicle, such as a bed wall. The cover may be acap or topper. The cap or topper may have one or more moveable panels orliftgates and one or more torsion elements. The one or more torsionelements assist with moving the liftgate and/or one or more panelsbetween a closed and open configuration and vice versa.

These teachings relate to a tonneau cover that includes a first panel, asecond panel, a hinge between the first panel and the second panel, anda torsion element between the first panel and the second panel. Thetorsion element applies an urging force onto one or both of the firstpanel and the second panel during movement of the first panel and/or thesecond panel about the hinge.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a vehicle and a tonneau cover.

FIG. 2 is a perspective view of a tonneau cover.

FIG. 3 is a bottom perspective view of a portion of the tonneau cover.

FIG. 4 is a top perspective view of a tonneau cover, with one of thepanels moved into an open configuration.

FIG. 5 is a detailed perspective view of the panel of FIG. 4 in the openconfiguration.

FIG. 6 is a bottom perspective view of a portion of the tonneau cover.

FIG. 7 is a top perspective view of a tonneau cover, with two of thepanels moved into an open configuration.

FIG. 8 is a detailed perspective view of the two panels of FIG. 7 in theopen configuration.

FIG. 9 is a bottom perspective view of a portion of the tonneau cover.

FIG. 10 is a top perspective view of a tonneau cover, with three of thepanels moved into an open configuration.

FIG. 11 is a detailed perspective view of the three panels of FIG. 10 inthe open configuration.

FIG. 12 is a bottom perspective view of a portion of the tonneau cover.

FIG. 13 is a top perspective view of a tonneau cover, with four of thepanels moved into an open configuration.

FIG. 14 is a perspective view of a vehicle and a cover.

FIG. 15 is a perspective view of a vehicle and a cover.

DETAILED DESCRIPTION

These teachings provide a cover. The cover may be an apparatus orassembly for at least partially covering or concealing at least aportion of a vehicle, such as a cargo area. The cover may be a tonneaucover, topper, cap, tent, or a combination thereof.

The cover may be attached, placed, supported, connected or made to reston one or more top surfaces of the one or more walls defining a cargoarea. The cover may be attached, placed, supported, connected, or madeto rest on one or more rails or supports that are attached or connectedto one or more surfaces of one or more walls defining the cargo area.The cover or one or more components thereof may be an aftermarketproduct that is/are attached to a vehicle by a vehicle owner. The coveror one or more components thereof (e.g., the one or more panels, torsionelements, frames, frame members, hinges, etc.) may be assembled,installed, and/or integrated into the vehicle or cargo area by an OEM(Original Equipment Manufacturer).

One or more of the features or elements of any of the covers disclosedand/or illustrated herein may be provided or combined with any cover,even though the combination or integration is not illustrated orexpressly disclosed herein. Moreover, one element or feature of thecover may be moved or repositioned into another area or feature of thecover. One or more features or elements of any of the covers disclosedand/or illustrated herein may be copied or duplicated. One or morefeatures or elements of any of the covers disclosed and/or illustratedherein may be removed or eliminated. One or more features or elements ofany of the covers disclosed and/or illustrated herein may be rearrangedinto other areas or positions relative to the vehicle depending on thespecific construction of the vehicle and/or cargo area. For example, anon-limiting example of this is that the torsion elements 86, 96illustrated between panels 24 d, 24 e in FIGS. 12 and 13 may be providedbetween any two other panels, such as panels 24 b, 24 c. And the torsionelement 26 b between panels 24 b, 24 c in FIG. 6 may be moved to theregion between panels 24 d, 24 e in FIGS. 12 and 13. Similarly,construction of one or more of the panels, frames, frame members,hinges, brackets, spacers, torsion elements, etc. may be repositioned,duplicated, removed, combined, separated, etc. without limitation.

The vehicle may be any vehicle. The vehicle preferably has a cargo areaor bed. The cargo area or bed may be any area or portion of a vehiclethat may be used for storing and/or transporting goods or cargo. Thecargo area may be a cargo box, bed, trunk, storage compartment, or acombination thereof. The cargo area may be located in a front portion ofa vehicle, a middle portion of a vehicle, and/or a rear portion of avehicle. The cargo area may be located behind or adjacent a passengerarea of a vehicle, where one or more passengers, occupants, and/ordrivers may sit. A cargo area may be a trailer that is configured to bepulled, towed, or pushed by a vehicle. The cargo area may be any part ofthe vehicle that has an open top. The cargo area or open top can be atleast partially closed or covered by a cover. The cargo area may be partof a pickup truck. The cargo area may be part of a utility task vehicleor utility terrain vehicle (UTV). In some configurations, the cargo areamay have another cover or top on it, and the cover according to theseteachings may be provided between the floor of the cargo area and thecover or top. For example, the cover according to these teachings may beprovided inside a vehicle or sport utility vehicle (SUV) to close orcover or conceal contends in the hatch, trunk, or other region of thevehicle.

The cover may be an assembly comprising one or more panels. A panel asused herein may be any of the one or more parts, portions, components,or sections of the cover that are moveable or can be moved relative toanother part, portion, component or section of the cover, a vehicle, acargo area, or a combination thereof. A panel may be a portion, region,or element, between two or more panels that does not move, like a spacerbar. A spacer may be a material, component, or member that is providedor located between or adjacent the one or more panels, hinges, frames,frame members, torsion elements, or a combination thereof. A spacer maybe provided between a panel and the cargo area or walls thereof toassist with mounting the cover to the cargo area. A spacer may beprovided to cover any gaps between the cover and cargo area. The one ormore panels may be a rigid section of the cover, a flexible section ofthe cover, a frame, a frame member, a spacer, a hinge, or a combinationthereof.

The one or more panels may be separate or discrete pieces that arejoined together with one or more hinges, spacers, torsion elements,frames, frame members, or other panels.

In some configurations, two or more panels may be defined in or within asingle panel. For example, a single panel may be provided that includesone or more living hinges that divide the single panel into two or morepanels. A living hinge may be a cutout, detent, notch, groove, channel,thinned-area, flexible material, or a combination thereof formed oradded to a panel. Two or more of such panels with one or more livinghinges may be combined to define the cover. A living hinge may be one ofthe hinges used in this application.

The one or more panels may be made of a suitable material, such asplastic, metal, foam, composite, wood, fiberglass, or a combinationthereof. The one or more panels may be substantially rigid, soft orflexible, bendable, resilient, or a combination thereof. The one or morepanels may comprise a core that is covered in a skin. The core may be aplastic material such as extruded polypropylene or foam. The skin may bea sheet or spray that covers the core. The skin may be TPU, TPV, TPE,and/or TPR. The one or more panels may be made of the same or similarmaterial as the cargo area or fenders so that the cover and the cargoarea and vehicle have a uniform appearance. The one or more panels maybe made of a single material or may be formed of multiple materials orcomponents that are assembled together. The one or more panels mayinclude one or more frames or frame members that provide strength andrigidity to the panels. The one or more hinges, torsion elements,spacers, frames, frame elements, or a combination thereof may be part ofthe panel or separate members. The one or more frames or frame membersmay be covered by a skin or over molded with a material to form the oneor more panels. The hinge and/or torsion elements may be over molded orcovered by a skin so that the cover has a uniform and sleek appearance,to cover or protect the hinge and/or torsion elements from wear and tearand/or bumping with objects inside the cargo area.

The one or more of the panels can be moved or repositioned relative toone another and/or relative to the cargo area or vehicle to move thecover or one or more panels thereof between a closed configuration andan open configuration and vice versa.

A closed configuration means that the one or more panels are arranged toat least partially conceal, block, hide, restrict, or otherwise preventsight, access, and/or entry to an inside of the cargo box. In the closedconfiguration, the one or more panels may be arranged to protect againstdirt, debris, fluid, sunlight, and/or other contaminants or items fromentering an inside of a cargo area. In the closed configuration, one ormore of the panels may be in a generally horizontal position, and freefrom being stacked or folded on top of another panel. The closedconfiguration may refer to one or more panels being in a closedconfiguration or to the entire cover assembly being in the closedconfiguration. In other words, one of the panels may be in the closedconfiguration (for example, a panel that is located near or adjacent tothe passenger area, while another panel (for example one that is locatedrearward of the closed panel, closer to the tailgate) is in the openconfiguration. A closed configuration may be when the one or more panelsrestrict more access into the cargo area than when the cover or panel isin an open configuration. In other words, a closed configuration maystill provide access into the cargo area, but the access or opening issmaller or less than when the cover or panel is in an openconfiguration. In the closed or partially closed configuration, one ormore of the panels may be in any non-horizontal position. A partiallyclosed configuration may be when the panel is more closed than a panelwhen the panel is in a partially open configuration. In some instances,a partially open configuration and a partially closed configuration maybe use synonymously.

An open configuration means that the one or more panels are arranged toat least partially provide access or entry to or into the cargo area oran inside thereof. In the open configuration, one or more of the panelsmay be moved or repositioned from the closed configuration to providesight and/or access to an inside of the cargo box. In the openconfiguration, one or more of the panels may be in any non-horizontalposition. In the open configuration, one or more of the panels may be ina generally horizontal position but may be stacked or folded on top ofone or more other panels. The open configuration may refer to one ormore panels being in an open configuration or to the entire coverassembly being in the open configuration. In other words, one of thepanels may be in the closed configuration (for example, a panel that islocated near or adjacent to the passenger area, while another panel (forexample one that tis located rearward of the closed panel, closer to thetailgate) is in the open configuration.

The one or more panels may be moved from a closed configuration to anopen configuration and vice versa by moving, repositioning, or otherwisechanging a position of one or more panels relative to one or more otherpanels, the cargo box, the vehicle, one or more hinges, or a combinationthereof. For example, a position of one or more of the panels can bechanged by moving, pivoting, folding, swinging, or otherwise turning orflipping one or more panels over or onto another one or more panelsabout one or more hinges, frames, panels, torsion elements, or acombination thereof. The one or more panels can be manually movedbetween the closed and open configurations. The one or more panels canbe automatically moved between the closed and open configurations viaone or more motors, cylinders, actuators, or a combination thereof.

The cover and/or the one or more panels may be an assembly comprised ofone or more frames or frame members, one or more hinges, one or moretorsion elements, one or more spacers, or a combination thereof.

The cover may include one or more frames. A panel may include one ormore frames. A frame may provide structure, rigidity, or stability tothe cover and/or reinforce the one or more panels. A frame may preventthe cover and/or one or more panels from twisting, bending, folding,deforming, collapsing, sagging, or otherwise moving in unintended areasor directions. In some configurations, one or more of the panels may befree of a frame. This may be the case if the panel is made from a rigidmaterial, such as a rigid injection molded or composite construction.However, some flexible panels may be free of a frame. In otherconfigurations, a frame may be over molded or covered with a skin toform or define a panel. One or more hinges and/or torsion elements maybe covered by the skin or over molded.

A frame may be an assembly or grouping of one or more frame members. Oneor more frame members may be provided at a front end, a rear end, or onone or more sides of the panel. A frame member may be provided at anangle or diagonal relative to other frame members. A frame member may beprovided generally parallel or perpendicular to other frame members. Afront end as used herein may be an end or edge of the panel or coverthat is located closer to a front of the cargo area or vehicle, relativeto an opposing end or edge of the panel or cover. A frame member may bean extrusion, stamping, or molding. A frame member may be constructed ormade of a metal, plastic, aluminum, and/or a composite. A frame or framemember may be a bar, rod, pipe, block, rail. A frame member may have anycross-sectional shape, like circular, square, etc. A frame member may behidden from view, for example, by a skin placed over the frame to givethe panel an integrated look when the panel is in the open and closedconfiguration. If the frame includes two or more frame members, theframe members may be arranged generally parallel to other frame members,generally perpendicular to other frame members, or at any angle relativeto one another. A panel or frame may include any number of frame members(e.g., one or more frame members, two or more frame members, three,four, five, etc. or more frame members). The frame members may beprovided on a B-side of the one or more panels, along a side orperimeter of the one or more panels, along an A-surface of the one ormore panels, or a combination thereof. A frame may be a picture-framethat surrounds the panel. In some instances, a panel may be completelyfree of any frames or frame members. This may be in situations where thepanel is injection molded, thermoformed, or otherwise rigid without theneed for additional frames, which may undesirably add weight to thepanel and/or cover. However, with the aid of one or more torsionelements, the additional weight may be compensated for by additionaland/or stronger torsion elements.

The cover may include one or more hinges. A panel may include one ormore hinges. A hinge may be a joint, turning point, juncture, axis,journal or other feature about which one or more panels or spacers canbe move, pivot, swing, bend, fold, roll, flex, displace, or otherwisechange position relative to one or more other panels, the cargo box, thevehicle, or a combination thereof. A hinge may allow or provide for theone or more panels to be moved between the open and closedconfiguration, or into a position in between the open and closedconfiguration.

A hinge may be provided between two panels. A hinge may define orseparate two adjacent panels. A hinge may also be attached to both afixed or nonmoving portion of the vehicle or cargo bed and to a panel ofthe cover.

A hinge may be comprised of one or more hinges or hinge portions. Ahinge may comprise a plurality of hinges provided adjacent one another,which may increase or provide additional movement, pivoting, or foldingof the one or more panels relative to each other and/or the vehicle.

A hinge may comprise one or more spacer bars. A spacer bar may beprovided between adjacent hinges. A spacer bar may increase spacingbetween adjacent panels connected to the panels; reinforce or providerigidity to the hinge assembly or cover or both. One or more torsionelements may be attached to or provided adjacent a spacer bar. One ormore of the torsion elements may be attached or connected to a spacerbar. A spacer bar may have the same material or construction as one ormore of the panels. The spacer bar may be plastic, metal, injectionmolded, extruded, or stamped.

A hinge may comprise one or more brackets attached to or made part ofthe one or more panels or hinges that turn on one or more pins. A hingemay be a living hinge formed or defined in one panel. This means thattwo or more panels may be part of one unitary panel but divided ordefined into separate panels by way of a living hinge. The one or morehinges may be made of an elastomeric and/or resilient material that isadded between two adjacent panels.

The cover may include one or more torsion elements. A panel may includeone or more torsion elements. A torsion element may provide a force,such as a torsional force, torque, assisting force, and/or urging forcethat influences or offsets a weight of the one or more panels. A torsionelement may function to reduce an amount of force required to move theone or more panels between a closed and an open configuration, and viceversa. A torsion element may assist with lifting or moving the cover orone or more panels between the closed configuration and the openconfiguration and then from the open configuration to the closedconfiguration. A torsion element may assist with lifting or moving thecover or one or more panels between a first horizontal position and asecond horizontal position. For example, one of the horizontal positionsmay be when a panel is in a closed configuration and another one of thehorizontal positions may be when the panel is moved and stacked on topof an adjacent position so that access is provided into the cargo area.

The one or more torsion elements may be one or more torsion rods,torsion bars, one or more torsion springs, or a combination thereof. Theone or more torsion elements may be one or more springs, compressionsprings, pistons and cylinders, pneumatic cylinders. The one or moretorsion elements may be a counterbalance. The one or more torsionelements may be made of spring steel. The one or more torsion elementsmay comprise a composite material, such as molded or extruded plastic.The one or more torsion elements may be coated in a suitable material toprevent rusting, to prevent the torsion element from rubbing against ordamaging a panel. The one or more torsion elements may be covered with askin or over mold. This may hide the torsion element from view and/orprotect the torsion element from wear and/tear and/or elements likerain, water, snow, etc. The skin or over mold may protect the torsionelement from damage from being bumped or hit by object in the cargo areaduring loading and/or unloading.

The torsion element may have opposing ends. One of the ends of thetorsion element may be directly, fixedly, connected or attached to apanel, bracket, frame, or frame member, or hinge. One of the ends may bedirectly, fixedly, connected or attached to another panel, bracket,frame, or frame member or hinge. One of the ends may be directly,fixedly, connected or attached to a fixed portion or non-movable portionof the vehicle or cargo area, such as a fender or wall defining thecargo area. One of the ends

One of the ends may be free from directly contacting a panel, bracket,frame, frame member, hinge, or fixed portion of the vehicle or cargoarea when the one or more panels are in the open and/or closedconfiguration. In this arrangement, the torsion element or end thereofmay come into contact with the panel, bracket, frame, frame member, orhinge or fixed portion of vehicle or cargo area during movement of thecover or one or more panels between the open and closed configurations.

For example, one of the ends may be directly connected or attached tothe one or more panels and/or frame members via a bracket, clamp,adhesive, weld, strap, bushing, retainer, undercut, flange, or acombination thereof. For example, one of the ends may be received into anotch, pocket, recess, cut out, bore, defined in the panel, framemember, spacer bar, hinge. Receiving the torsion element or end thereofinto a recess, notch, cutout, or depression may be advantageous toincrease packaging space inside the cargo area when the cover is in aclosed configuration. Receiving the torsion element or end thereof intoa recess, notch, cutout, or depression may be advantageous to decreasepackaging space of the cover when the cover and panels thereof arefolded into an open configuration. The notch, pocket, recess, cut out,bore, etc., may be formed into one or more panels, hinges, spacer bars,or a combination thereof.

The one or more torsion elements may be attached to adjacent orjuxtaposed panels or frame members. The one or more torsion elements maybe connected or attached to opposite sides of adjacent panels. Forexample, one end of a torsion element may be attached to a side of thepanel on the driver side of the panel and another end of the torsionelement may be attached to a side of the other panel on the passengerside of the panel. The one or more torsion elements may be connected orattached to the same sides of adjacent panels. For example, one end of atorsion element may be attached to a side of the panel on the driverside of the panel and another end of the torsion element may be attachedto a side of the other panel also on the driver side of the panel. Insome configurations, one end of a torsion element may be attached to aleading end of one panel and another end of the torsion element may beattached to a trailing end or edger of the adjacent panel. In someconfigurations, there may be one or more torsion elements that areconnected between two panels that have another panel provided betweenthe two connected panel.

One or both of the ends may be free from being directly connected orattached to a panel. Instead, one or both of the ends may be locatedadjacent to or juxtaposed with a panel, panel assembly, frame, framemember, hinge, spacer bar, or a combination thereof.

The connecting region of a torsion element, which may be defined as anyportion of the torsion element between the ends thereof, may be attachedor connected to a panel, panel assembly, frame, frame member, hinge,hinge assembly, spacer bar, or a combination thereof. The connectingregion of the torsion element, or any portion of the torsion element maybe connected or attached to a panel, panel assembly, frame, framemember, hinge, plurality of hinges, spacer bar, cargo area, bed,vehicle, topper, or a combination thereof with one or more brackets,straps, fasteners, or a combination thereof. The connecting region of atorsion element may be free from being attached or connected to a panel,panel assembly, frame, frame member, hinge, hinge assembly, spacer bar,or a combination thereof. Instead, the connecting region of a torsionelement, may be located adjacent to or juxtaposed to a panel, panelassembly, frame, frame member, hinge, hinge assembly, spacer bar, or acombination thereof.

The one or more torsion elements may be arranged along a B-side of theone or more panels or cover so that when the cover and/or panels are ina closed configuration the one or more torsion elements are not visiblefrom outside of the vehicle. The one or more torsion elements may bevisible from outside of the vehicle when one or more of the panels aremoved into an open configuration. The one or more torsion elements maybe arranged along a B-side of the one or more panels or cover so thatthe torsion element is visible. The one or more torsion elements may bearranged along a A-side of the one or more panels and may or may not becovered with a skin or other material.

The one or more torsion elements may be centered about a center line ofthe one or more panels, cover, cargo area, and/or vehicle.Alternatively, the one or more torsion elements may be offset towardsone side of the panel, cover, cargo area, and/or vehicle (e.g., towardsa driver or passenger side thereof).

The cover may include two or more torsion elements. There may be two ormore torsion elements arranged between adjacent panels, which may beadvantageous to assist in moving the panels when the panels aresubstantially heavy. For example, two or more torsion elements may beprovided at or near a front end of the cargo area (adjacent to thepassenger area) to assist in lifting or moving a plurality of the panelsthat have been moved or stacked on top of one another. In someconfigurations that include two or more torsion elements connectingadjacent panels, the torsion elements may be adjacent to one another,cross over or under one another, or both.

A torsion element may be provided between two panels that are connectedtogether with a hinge. Alternatively, in some configurations, the covermay be free of a torsion element provided in a location where two panelsare joined with a hinge.

The one or more torsion elements may be formed, bent, or curved in a waythat when the one or more panels or cover are in a closed configuration,an amount of packaging space inside of the cargo area is not reduced ortaken up by the torsion element. This means that the one or more torsionelements are provided adjacent or juxtaposed with a bottom or B-side ofthe one or more panels, hinges, frames, frame members, spacers, of acombination thereof.

The one or more torsion elements may have a shape that generallyresembles a “Z”, “S”, “U”, “C” or any other regular or irregular shape.

A vehicle 10 is illustrated in FIG. 1. The vehicle 10 comprises a bed orcargo area 12 and a passenger cab 14. The cargo area 12 is defined by aplurality of walls that include: opposing side walls 16 a, 16 b, a frontwall 18 located adjacent the passenger cab 14, and a rear wall ortailgate 20 that opposes the front wall 18. The front wall 18 of thecargo area 12 may be a shared or common wall with a wall of thepassenger cab 14. These vehicles may be one piece or uni-body vehicles.In other vehicles, the front wall 18 may be a separate wall, segment, orportion of the vehicle from a rear wall of the passenger cab 14. Thefront wall 18 may also provide access to the passenger cab 14 via a passthrough or fold down wall or door. The cargo area 12 has a bottom orfloor 13 that is surrounded by the walls 16 a, 16 b, 18, 20. The bottomor floor 13 is opposite an open end of the cargo area 12.

A cover 22 may be applied on top of or over the open or top end of thecargo area 12. The cover 22 may include one or more panels. In FIG. 1,the cover 12 includes four panels 24 a, 24 b, 24 c, and 24 d. However,the cover 12 may include any number of panels, including as little asonly one panel (i.e., no more than one panel; See FIG. 14 for example).The panels may be separated from one another by one or more hinges 26 a,26 b, and 26 c that allow respective panels to move relative to eachother, other panels, the cargo area 12, and/or the vehicle 10. The cover22 and panels 24 a, 24 b, 24 c, 24 d are illustrated in the closedconfiguration.

For purposes of orientation, panel 24 a may be referred to as the firstor rear panel; panel 24 b may be referred to as the second panel; panel24 c may be referred to as the third panel; panel 24 d may be referredto as the fourth or front panel.

Another cover 22 illustrated in FIG. 2 has five panels 24 a, 24 b, 24 c,24 d, and 24 e. The panels 24 a, 24 b, 24 c, 24 d, and 24 e areseparated from each other by one or more hinges 26 a, 26 b, 26 c, and 26d that allow for the panels to move relative to each other, otherpanels, the cargo area 12, and/or the vehicle 10. The cover 22 andpanels 24 a, 24 b, 24 c, 24 d, 24 e are illustrated in the closedconfiguration.

FIG. 3 illustrates the first panel 24 a and the second panel 24 b of thecover 22. The panels 24 a, 24 b are separated by hinge 26 a. Hinge asused throughout this disclosure may include a single hinge or mayinclude an arrangement or series of a plurality of adjacent hinges. Ahinge may also include one or more spacers or spacer bars betweenadjacent hinges. For example, a spacer bar between adjacent hinges isillustrated and described below in FIG. 9.

One or more of the panels 24 a, 24 b may comprise a respective frame 28a, 28 b. The frame 28 a of panel 24 a may include one or more framemembers, that may include: a pair of first frame members 30, 32 and apair of second frame members 34, 36. The frame members 30, 32, 34, 36may be arranged as a picture frame on a B-side of the panel 24 a. Theframe 28 b of panel 24 b may include one or more frame members, that mayinclude: a pair of first frame members 38, 40 and a pair of second framemembers 42, 44. The frame members 38, 40, 42, 44 may be arranged as apicture frame on a B-side of the panel 24 b.

A torsion element 46 may be provided at the first and second panels 24a, 24 b. For example, the torsion element 46 may be connected orattached to the first panel 24 a, the second panel 24 b, to one or bothof the frames 28 a, 28 b, to one or more frame members of the frames 28a, 28 b, or a combination thereof. The torsion element 46 may extendalong a B-side of the panels 24 a, 24 b. The B-side is the side thatfaces an inside of the cargo area 12 or the floor 13 of the cargo area12 (FIG. 1).

The torsion element 46 may have any suitable shape. In this example, thetorsion element 46 has a generally “Z” shape. The torsion element 46 mayinclude a first end 48 and an opposing second end 50. The first end 48may be adjacent, connected, or attached to the first panel 24 a, theframe 28 a, and/or to one or more of the frame members of frame 28 a,such as frame member 36. The second end 50 may be adjacent, connected,or attached to the second panel 24 b, the frame 28 b, and/or to one ofthe frame members of frame 28 b, such as frame member 42. The ends 48,50 may engage bores, pockets, recesses, openings, or other attachment orconnection features defined in the corresponding panels 24 a, 24 b,frames 28 a, 28 b, frame members 36, 48 or may be connected thereto viaa bracket or other mounting mechanism or fasteners.

In some configurations, one or both of the ends 48, 50 of the torsionelement 46 are not attached or are free from being attached or connectedto one or more of the panels, frames, frame members. Instead, one orboth of the ends may be located adjacent to the panels, frames, framemembers, or a combination thereof. In such configurations, the one ormore ends may press, be pressed against, or come into contact (direct orindirect via one or more other panels, features, elements, spacers,etc.) with the respective panel, frame, frame members, or a combinationthereof during movement of the one or more panels between the open andclosed configuration and thus apply the torsional or assisting forcethereon to assist with further lifting or moving the one or more panelsinto or towards the closed or open position. Another portion of thetorsion element, such as the connecting piece discussed below, may ormay not be attached or connected to the frame, frame member, panel,cover, cargo area, and/or vehicle to maintain the relative position ofthe torsion element relative to the cover and/or vehicle. Thisdiscussion referring to the ends and connecting piece being connected toor being free from connecting to the panels or components thereofapplies to any of the torsion element configuration or applicationsdisclosed herein, no matter their location on the cover. This alsoapplies to the topper configuration illustrated in FIG. 15.

The torsion element 46 may include a connecting piece 52 extendingbetween the two ends 48, 50. The connecting piece 52 may be arranged orlocated in a region of the hinge 26 a. The connecting piece of any ofthe torsion elements described herein may be any region of the torsionelement 46 between the ends thereof. The torsion element 46 may be asolid, integral member that includes the ends 48, 50 and connectingpiece 52. The torsion element may comprise of two or more pieces thatare connected together. For example, one or both ends may be connectedto a connecting piece. In some configurations, the torsion element 46,connecting piece 52 and/or end thereof may be attached or connected toone or more of the hinges or spacer bars located in the hinge.

The torsion element 46 substantially centered about a centerlongitudinal axis 47 of the first panel 24 a and/or the second panel 24b. However, in some configurations, the torsion element 46 may beshifted or arranged towards one side 49 of the cover or another side 51,which may be passenger and driver sides in vehicle position.

FIGS. 4 and 5 illustrate the first or rear panel 24 a moved into theopen configuration. In this position, the A-surface of the first panel24 a faces the A-surface of the second panel 24 b. The first panel 24 ahas been moved, pivoted, or otherwise folded up, over, and/or onto thesecond panel 24 b at or about the hinge 26 a. During movement of thefirst or rear panel 24 a from the closed configuration (position in FIG.3) to the open configuration (position in FIGS. 4 and 5), the torsionelement 46 assists in moving, pivoting, urging or otherwise folding thefirst or rear panel 24 a up, over, and about the hinge 26 a.

The torsion element 46 assists in moving pivoting, urging or otherwisefolding the panel 24 a because the torsion element 46 is alreadypreloaded, twisted, or otherwise configured to store torque when thepanel is in a closed configuration or in an at least partially closedconfiguration. As the panel 24 a begins to be moved from the closedconfiguration of FIG. 3, the torsion element 46 wants to unwind or twistin the same rotational direction the panel is being moved, thus urgingor applying an assisting, urging, or torsional force onto the panel 24 awhich helps to move the panel 24 a from the closed configurationupwardly to a neutral position, which may a position of the panel 24 aat a location somewhere between the closed configuration and the openconfiguration. For example, the neutral position may be when the panel24 a is generally or substantially vertical relative to the adjacentpanel 24 b. In the neutral position, little or no torque is loaded orstored by the torsion element 46. As the first panel 24 a continues tobe moved, lowered or dropped down onto the second panel 24 b asillustrated in FIGS. 4 and 5, the torsion element 46 may once again betwisted or wound up and store torque. Then, when the first panel 24 a ismoved from the open configuration (FIG. 4) back into the closed position(FIG. 3), the torsion element 46 once again wants to unwind or untwistand urge or apply an assisting or urging force onto the panel 24 a toassist in moving the panel 24 a back into the neutral position. As thepanel 24 a is then dropped or lowered back into the closed configuration(FIG. 3), the torsion element 46 is once again wound or twisted andstores energy. Depending on the amount of torque stored by the torsionelement 46, the torsion element 46 may be able to move or urge the panel24 a from the closed configuration (FIG. 3) to the neutral position oreven to the open configuration (FIG. 4, 5) with little or no assistancefrom an operator. Similarly, depending on the amount of torque stored bythe torsion element 46, the torsion element 46 may be able to move orurge the panel 24 a from the open configuration (FIG. 4, 5) to theneutral position or even to the closed configuration (FIG. 3) withlittle or no assistance from an operator. The aforementioned descriptionof the torsion element 46 is applicable to any of the torsion elementsdescribed herein and any of the covers described herein.

FIG. 6 illustrates the second panel 24 b and the third panel 24 c ofcover 22. The panels 24 b, 24 c are separated by hinge 26 b. Each of thepanels 24 b, 24 c may comprise a frame 28 b, 28 c. The frame 28 b ofpanel 24 b may include one or more frame members, that may include: apair of first frame members 38, 40 and a pair of second frame members42, 44. The end 50 of the torsion element 46 is shown engaging panel 24b, as was discussed above in the previous FIGS. 3-5. The frame 28 c ofpanel 24 c may include one or more frame members, that may include: apair of first frame members 54, 56 and a pair of second frame members58, 60. While no torsion element is shown extended and/or connectingpanels 24 b, 24 c and/or frames 28 b, 28 c, it is understood that one ormore torsion elements may extend between and connect the panels 24 b, 24c, the frames 28 b, 28 c, one or more frame members, or a combinationthereof.

FIGS. 7 and 8 show the second panel 24 b in the open configuration,where the panel 24 b has been moved, folded, or otherwise pivoted abouthinge 26 b. In this open configuration, the first or rear panel 24 a isprovided between the second and third panels 24 b, 24 c, and both panels24 a, 24 b are folded or stacked on top of the third panel 24 c.

FIG. 9 illustrates the third panel 24 c and the fourth panel 24 d of thecover. The panels 24 b, 24 c are separated by hinge 26 c. The hinge 26 cincludes a plurality of hinge members 27 that are connected to a spacerbar 29 therebetween. Such a hinge that includes hinge members and one ormore spacers bars may be provided in any of the hinges and coversdisclosed herein in any location on the cover. Each of the panels 24 c,24 d may comprise a frame 28 c, 28 d. The frame 28 c of panel 24 c mayinclude one or more frame members, that may include: a pair of firstframe members 54, 56 and a pair of second frame members 58, 60. Theframe 28 d of panel 24 d may include one or more frame members, that mayinclude: a pair of first frame members 62, 64 and a pair of second framemembers 66, 68.

A torsion element 70 may be connected or attached to the third panel 24c and the fourth panel 24 d, to frame 28 c, 28 d, to one or more framemembers of the frames 28 c, 28 d, or a combination thereof. The torsionelement 70 may extend along a B-side of the panels 24 c, 24 d when thepanels 24 c, 24 d and/or cover 22 are in the closed configuration.

The torsion element 70 may comprise a generally “Z” shape or ameandering shape that includes a first end 72 and second end 74. Thefirst end 72 may be adjacent, connected, or attached to the third panel24 c, the frame 28 c, and/or to one or more of the frame members offrame 28 c, such as frame member 60. The second end 74 may be adjacent,connected, or attached to the fourth panel 24 d, the frame 28 d, and/orto one of the frame members of frame 28 d, such as frame member 66. Theends 72, 74 may engage bores, pocket, or openings defined in thecorresponding panels 24 c, 24 d, frames 28 c, 28 d, frame members 60, 66or may be connected thereto via a bracket or other mounting mechanism orfasteners. The torsion element 70 may include a connecting piece 76extending between the two ends 72, 74 and located in a region of thehinge 26 c. The torsion element 70 may be a solid, integral member thatincludes the ends 60, 66, and connecting piece 76.

FIGS. 10 and 11 illustrate the first 24 a, second 24 b, and third panels24 c of the cover 22 moved into the open configuration. The third panel24 c, which has the first and second panels 24 a, 24 b stacked on top ofit (refer to FIG. 8) is folded onto the fourth panel 24 a about hinge 26c. The torsion element 70 assists in moving the weight of the threepanels 24 a, 24 b, 24 c into the open configuration of FIGS. 10 and 11due to its preloading (pre-twisting) and ability to store force. Thus,moving or pivoting the weight of the three panels from the position inFIG. 9 to the position in FIGS. 10 and 11 (or to a neutral position) ismuch easier compared to if there was no torsion element therebetween.

FIG. 12 illustrates the fourth panel 24 d and the fifth panel 24 e ofthe cover. The panels 24 d, 24 e are separated by hinge 26 d. Each ofthe panels 24 d, 24 e may comprise a frame 28 d, 28 e. The frame 28 d ofpanel 24 d may include one or more frame members, that may include: apair of first frame members 62, 64 and a pair of second frame members66, 68. The frame 28 e of panel 24 e may include one or more framemembers, that may include: a pair of first frame members 78, 80 and apair of second frame members 82, 84

A torsion element 86 may be connected or attached to the fourth panel 24d and the fifth panel 24 e, to a frame 28 d, 28 e, or to one or moreframe members of the frames 28 d, 28 e like members 68 and 82.

The torsion element 86 may comprise a generally “Z” shape and includes afirst end 88 and a second end 92. The first end 99 is adjacent,connected, or attached to the fourth panel 24 d, the frame 28 d, to oneor more of the frame members of frame 28 d, such as frame member 62, orto a bracket 90 connected to one of the frame members, like frame member62. The second end 92 may be adjacent, connected, or attached to thefifth panel 24 e, the frame 28 e, and/or to one of the frame members offrame 28 e, such as frame member 80, or to a bracket 94 connected toframe member 80.

Another torsion element 96 may be connected or attached to the fourthpanel 24 d and the fifth panel 24 e and/or to a frame 28 d, 28 e or oneor more frame members of the frames 28 d, 28 e. The torsion element 96crosses the torsion element 86 in a region of the hinge 26 d. Thetorsion element 96 may comprise a generally “Z” shape, and includes afirst end 98 adjacent, connected, or attached to the fourth panel 24 d,the frame 28 d, to one or more of the frame members of frame 28 d, suchas frame member 64, or to a bracket 100 connected to frame member 64.The torsion element 96 may include a second end 102 adjacent, connected,or attached to the fifth panel 24 e, the frame 28 e, and/or to one ofthe frame members of frame 28 e, such as frame member 78, or to abracket 104 connected to frame member 78.

FIG. 13 shows the first 24 a, the second 24 b, the third panel 24 c andthe fourth panel 24 d of the cover in the open configuration. The fourthpanel 24 d, which has the first, second, and third panels 24 a, 24 b, 26c stacked on top of it (refer to FIG. 11) is folded onto the fifth panel24 e about hinge 26 d. The torsion element 86, 96 assists in moving theweight of the four panels 24 a, 24 b, 24 c, 24 d into the openconfiguration due to their preloading (pre-twisting) and ability tostore force. Thus, moving or pivoting the weight of the four panels fromthe position in FIG. 12 to the position in FIG. 13 (or to a neutralposition) is much easier compared to if there was no torsion elementstherebetween. Two torsion elements 86, 96 are provided due to theincreased weight of four panels compared to three panels in the previousfigures. It is understood, that depending on the number of stackedpanels and thus the weigh to the stacked panels, additional torsionelements may be provided. For example, three, four, five, etc. torsionelements may be used.

FIGS. 12 and 13 illustrate attaching the torsion elements to the sideframe members 62, 64, 78, 80 via brackets. This type of attachment maybe used in the other panels 24 a, 24 b, 24 c. Alternatively, attachingthe ends of the torsion elements directly to the frame members as is thecase in panels 24 a, 24 b, 24 c may be incorporated into the panels 24d, 24 e. However, due to the increased weight of the four panels stackedon top of each other, it may be preferred to attach the torsion elementsto the side frame members.

While not illustrated, one or more torsion elements may be between thepanel 24 e, frame 28 e, the frame member 84 and/or frame members 78, 80and the cargo area 12 or vehicle 10 so that the fifth panel 28 e and thepanels stacked thereon can be moved or pivoted. This means that anotherhinge would be provided at or near the edge of the panel 24 e where theframe member 84 is located.

It is also understood that there could be more panels than just the fiveillustrated in the figures. Also, some covers may only include onepanel. In such configurations, the one panel may have a hinge connectedto it and to the cargo area. One or more torsion elements can beconnected to the single panel and the cargo area for assisting in movingthe single panel between an open and closed configuration.

Referring to FIG. 14, another vehicle 10 is illustrated that may besubstantially similar to the vehicle of the previous figures. Thevehicle 10 comprises a bed or cargo area 12 and a passenger cab 14. Thecargo area 12 is defined by a plurality of walls that include: opposingside walls 16 a, 16 b, a front wall 18 that is located adjacent to thepassenger cab 14, and a rear wall or tailgate 20. The front wall 18 maybe a shared wall or portion with the passenger cab 14 or the front wall18 may be a separate wall from the passenger cab 14.

A cover 122 may be applied or located on top of the open end of thecargo area 12. The cover 122 of FIG. 14 includes only one panel 124(i.e., no more than one panel). The panel 124 is connected or attachedto the cargo area 12 or to one or more walls thereof via one or morehinges, brackets, or other mechanisms that allow the cover 122 or panel124 to move, pivot, or tilt relative to the cargo area 12 between aclosed and the illustrated open configuration. In the closedconfiguration, the cover 122 or single panel 124 may be in a generallyhorizontal position.

The cover 122 may have one or more shocks 126. A shock 126 may belocated on each side of the vehicle 10 (i.e., on the driver side and theillustrated passenger side) or the cover 122 may include only one shock(i.e., on the driver side or the illustrated passenger side). The shock126 however, can be located anywhere, even at a center portion of thecover 122. The shock 126 may be a torsion element as used herein toassist with raising and lowering the cover 122 between the closed andopen configuration. The shock 126 may be a torsion element as usedherein to assist with maintaining a position the cover 122 and/or panel124 in a position between the closed and open configuration. The shock126 may restrict or prevent the cover 122 or panel 124 from falling orslamming into the closed position when the cover 122 or panel 124 isbeing lowered into the closed configuration.

The cover 122 may include one or more torsion elements 128. Torsionelement 128 may be in addition to the one or more shocks 126 or insteadof the one or more shocks 126. The torsion element 128 may be located ator adjacent to the front wall 18 of the cargo area 12. The torsionelement 128 may be located at or adjacent to the hinge, bracket, orother mechanism that allows the cover 122 or panel 124 to move or tilt.The torsion element 128 may be attached directly to the rear wall 18, toone or both of the side walls 16 a, 16 b, or a combination hereof. Theone or more torsion elements 128 may include end portions that areattached to or located adjacent to the panel 124 and come into connectwith the panel 124 during movement of the panel 124 between closed andopen configurations. The one or more torsion elements 128 may includeend portions that are always attached to the panel 124. The one or moretorsion elements 128 may include a connecting region between the endsthereof that is located adjacent to the front wall 18, side walls 16 a,16 b, panel 124, brackets, hinges, or a combination thereof.

Referring to FIG. 15, another vehicle 10 is illustrated that may besubstantially similar to the vehicle of the previous figures. Thevehicle 10 comprises a bed or cargo area 12 and a passenger cab 14. Thecargo area 12 is defined by a plurality of walls that include: opposingside walls 16 a, 16 b, a front wall 18 that is located adjacent to thepassenger cab 14, and a rear wall or tailgate 20. The front wall 18 maybe a shared wall or portion with the passenger cab 14 or the front wall18 may be a separate wall from the passenger cab 14.

A cover 222 may be applied on top or over the open end of the cargo area12. The cover 222 may be a topper or cap that includes a rear panel orlift gate 224 and one or more side panels 226 a, 226 b. One or more ofthe panels 224, 226 a, 226 b may be movable or pivotable between andopen and closed configuration. In FIG. 15, the rear panel 224 is movableand is in an open configuration.

The cover 122 may have one or more shocks 228. A shock 228 may belocated on each side of the vehicle 10 (i.e., on the driver side and thepassenger side) or the cover 222 may include only one shock (i.e., onthe driver side or the illustrated passenger side). The shock 228however, can be located anywhere, even at a center portion of the cover222. The shock 228 may be a torsion element as used herein to assistwith raising and lowering the cover 222 between the closed and openconfiguration. The shock 228 may be a torsion element as used herein toassist with maintaining a position the cover 222 and/or panel 224 in aposition between the closed and open configuration. The shock 228 mayrestrict or prevent the cover 222 or panel 224 from falling or slamminginto the closed position when the cover 222 or panel 224 is beinglowered into the closed configuration.

The cover 222 may include one or more torsion elements 230. Torsionelement 230 may be in addition to the one or more shocks 228 or insteadof the one or more shocks 228. The torsion element 230 may be located ator adjacent to the front wall 18 of the cargo area 12. The torsionelement 230 may be located at or adjacent to the hinge, bracket, orother mechanism that allows the cover 222 or panel 224 to move or tilt.The torsion element 230 may be attached directly to the rear wall 18, toone or both of the side walls 16 a, 16 b, or a combination hereof. Theone or more torsion elements 230 may include end portions that areattached to or located adjacent to the panel 224 and come into connectwith the panel 224 during movement of the panel 224 between closed andopen configurations. The one or more torsion elements 230 may includeend portions that are always attached to the panel 224. The one or moretorsion elements 230 may include a connecting region between the endsthereof that is located adjacent to the front wall 18, side walls 16 a,16 b, panel 224, brackets, hinges, or a combination thereof.

It is understood that any method steps can be performed in virtually anyorder. Moreover, one or more of the method steps can be combined withother steps; can be omitted or eliminated; can be repeated; and/or canseparated into individual or additional steps.

The explanations and illustrations presented herein are intended toacquaint others skilled in the art with the invention, its principles,and its practical application. The above description is intended to beillustrative and not restrictive. Those skilled in the art may adapt andapply the invention in its numerous forms, as may be best suited to therequirements of a particular use.

Accordingly, the specific embodiments of the present invention as setforth are not intended as being exhaustive or limiting of the teachings.The scope of the teachings should, therefore, be determined not withreference to this description, but should instead be determined withreference to the appended claims, along with the full scope ofequivalents to which such claims are entitled. The omission in thefollowing claims of any aspect of subject matter that is disclosedherein is not a disclaimer of such subject matter, nor should it beregarded that the inventors did not consider such subject matter to bepart of the disclosed inventive subject matter.

Plural elements or steps can be provided by a single integrated elementor step. Alternatively, a single element or step might be divided intoseparate plural elements or steps.

The disclosure of “a” or “one” to describe an element or step is notintended to foreclose additional elements or steps.

While the terms first, second, third, etc., may be used herein todescribe various elements, components, regions, layers and/or sections,these elements, components, regions, layers and/or sections should notbe limited by these terms. These terms may be used to distinguish oneelement, component, region, layer or section from another region, layeror section. Terms such as “first,” “second,” and other numerical termswhen used herein do not imply a sequence or order unless clearlyindicated by the context. Thus, a first element, component, region,layer or section discussed below could be termed a second element,component, region, layer or section without departing from theteachings.

Spatially relative terms, such as “inner,” “outer,” “beneath,” “below,”“lower,” “above,” “upper,” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. Spatiallyrelative terms may be intended to encompass different orientations ofthe device in use or operation in addition to the orientation depictedin the figures. For example, if the device in the figures is turnedover, elements described as “below”, or “beneath” other elements orfeatures would then be oriented “above” the other elements or features.Thus, the example term “below” can encompass both an orientation ofabove and below. The device may be otherwise oriented (rotated 90degrees or at other orientations) and the spatially relative descriptorsused herein interpreted accordingly.

The disclosures of all articles and references, including patentapplications and publications, are incorporated by reference for allpurposes. Other combinations are also possible as will be gleaned fromthe following claims, which are also hereby incorporated by referenceinto this written description.

1) A tonneau cover for at least partially covering a cargo area of avehicle, the cargo area having a plurality of side walls, the tonneaucover comprising: a first panel; a second panel; a hinge between thefirst panel and the second panel; and a torsion element between thefirst panel and the second panel. wherein the torsion element applies anurging force onto one or both of the first panel and the second panelduring movement of the first panel and/or the second panel about thehinge. 2) The tonneau cover of claim 1, wherein the torsion element hasa Z shape. 3) The tonneau cover according to claim 1, wherein thetorsion element is a torsion bar. 4) The tonneau cover according toclaim 1, wherein the torsion bar is substantially centered about acenter longitudinal axis of the first panel and/or the second panel. 5)The tonneau cover according to claim 1, wherein the torsion element is atorsion spring. 6) The tonneau cover according to claim 1, wherein thetorsion element is a compression spring. 7) The tonneau cover accordingto claim 1, wherein the hinge extends along an axis that generallyperpendicular to a longitudinal axis of the vehicle. 8) The tonneaucover according to claim 1, wherein the torsion element is attached tothe first panel or to the second panel. 9) The tonneau cover accordingto claim 1, wherein the torsion element is free from direct attachmentto the first panel or to the second panel. 10) The tonneau coveraccording to claim 1, wherein the first panel comprises a frame, and thetorsion element is attached to the frame. 11) The tonneau coveraccording to claim 10, wherein the frame comprises a recess into whichthe torsion element is at least partially received. 12) The tonneaucover according to claim 9, wherein a bracket is attached to the frame,and the torsion element is attached to the bracket. 13) The tonneaucover according to claim 1, wherein a second torsion element is providedbetween the first panel and the second panel, and the second torsionelement applies an urging force onto one or both of the first panel andthe second panel during movement of the first panel and/or the secondpanel. 14) The tonneau cover according to claim 13, wherein the torsionelement and the second torsion element cross each other in a regionbelow the hinge. 15) The tonneau cover according to claim 1, wherein thetonneau cover comprises a third panel and a second hinge that separatesthe second panel and the third panel, wherein the tonneau cover is freeof a torsion element that extends between the second panel and the thirdpanel. 16) The tonneau cover according to claim 15, wherein the tonneaucover comprises a fourth panel and a third hinge that separates thethird panel and the fourth panel, wherein the tonneau cover comprises asecond torsion element that extends between the third panel and thefourth panel. 17) The tonneau cover according to claim 16, wherein thetonneau cover comprises a fifth panel and a fourth hinge that separatesthe fourth panel and the fifth panel, wherein the tonneau covercomprises a fourth torsion element that extends between the fourth paneland the fifth panel. 18) The tonneau cover according to claim 17,wherein the tonneau cover comprises a fifth torsion element that extendsbetween the fourth panel and the fifth panel. 19) The tonneau coveraccording to claim 17, wherein the fourth and fifth torsion elementscross each other. 20) The tonneau cover according to claim 19, whereinthe fourth and fifth torsion elements have ends that are secured to aframe of the respective fourth and fifth panels.